Problems with a "miss" on a 560 V8

[KLP 92]

I have a problem with a 560 V8, the car has a miss. The miss isn't noticable when the car is idling in neutral or park. When i hit the gas, while the car is in neutral, i can feel the miss in the engine. As soon as i put the car in drive or reverse the car begins to almost judder with the miss. The car is also sluggish, doesn't drive like a V8.

The previous owner had tried to have it rectified and changed a new distributor cap, rotor arm, ignition leads, new plugs, new fuel injectors but the problem is still there.

I've checked the plugs to see if there was oil or excessive petrol on the plugs but they are all fine. The car's not using any oil or water and there is no mixing. The oil pressure is just under 2 when the engine is hot, so no problem there either.

Any ideas on what it could be?

 

[Thmsshaun]

Do these have electronic ignition?

Or are they points & condensor?


If its the later may be worth checking them.

 

[GregE240]

KLP,

Don't know about the '560, but my 500 has 2 dizzy caps? One on each bank? Could it be that only 1 has been changed, and you've got one left thats still faulty?

If so, go for the BOSCH parts - about 2/3 the cost of the same thing but with an MB part number stamped on it?

HTH,
Greg

 

[KLP 92]

It is an electronic ignition on this model.

Its inly got 1 distributor cap, which has been changed along with the rotor arm.

Looks like another trip to George Fraser's......

 

[guydewdney]

Fuel pressure low - a problem on the early 500 140 series I know...

replace fuel filter?

Nice clean new 97 octane fuel make any difference?

 

[KLP 92]

Cheers for the advice. I dropped the car to George Fraser today and asked him to check over the car and identify the fault.

I will let you know what the problem is when i pick the car up.

 

[Vlad]

Fuel distributor???....although its not the same car, I believe that the injection technology used on the 560 is the same as a W124 300E. I've had to replace mine recently due to similar problems that you mention. It transpired that the fuel distributor was bunged up with crud from the fuel lines which was then causing over fuelling on cylinder 1. No way of cleaning it out either and it only happend after I had run some injector cleaner through the fuel lines....must have shifted some crud in the lines which then got stuck in the fuel distributor...expensive lesson!!!